scripts/install.sh: add special case for Parrot Security (#14487)

Their `os-release` doesn't follow convention.
Fixes #10778

Signed-off-by: Erisa A <erisa@tailscale.com>

scripts/installer.sh

@@ -68,6 +68,14 @@ main() {
 				if [ -z "${VERSION_ID:-}" ]; then
 					# rolling release. If you haven't kept current, that's on you.
 					APT_KEY_TYPE="keyring"
+				# Parrot Security is a special case that uses ID=debian
+				elif [ "$NAME" = "Parrot Security" ]; then
+					# All versions new enough to have this behaviour prefer keyring
+					# and their VERSION_ID is not consistent with Debian.
+					APT_KEY_TYPE="keyring"
+					# They don't specify the Debian version they're based off in os-release
+					# but Parrot 6 is based on Debian 12 Bookworm.
+					VERSION=bookworm
 				elif [ "$VERSION_ID" -lt 11 ]; then
 					APT_KEY_TYPE="legacy"
 				else